Fashions are meant to please, we'd all agree about that. But there's a whole category of fashion with a more complex aim. Think of the "beauty" spots of the 18th century – black moles are normally not considered beautiful but presumably emphasised the pallor of the surrounding complexion. Then there's deliberately torn or faded jeans, or the carefully trailing shoelace: their wearers aren't trying to please but to show they're too cool to care – and if it annoys their stuffy old seniors, so much the better.

The wayward single strand of hair; the bra strap that is actually meant to show – I don't know where they'd be without disapproving oldies to object to them. People my age keep the partings in their hair the same colour as the rest, to make it all look natural; the young have deliberately dark partings to make it clear that it isn't. I'm not sure whether the people who actually have their buttocks enlarged – when many of the rest of us ache for the answer "No" to "Does my bum look big in this?" – come into that category, but one of the latest, the T-shirt that is meant to show a bit below the jersey or jacket, certainly does.

The poet Robert Herrick explained how "a sweet disorder in the dress" did "more bewitch him than when art / Is too precise in every part". Poor sap, didn't he realise the disorder was a precise art?